"He has not been seen since the snow and the arctic blast have pummeled the Eastern Seaboard in America, turning it into a frozen tundra," reported Fox News's Glenn Beck, who also tastefully suggested hara-kiri for climate scientists.

As a scientific proposition, claiming that heavy snow in the mid-Atlantic debunks global warming theory is about as valid as claiming that the existence of John Edwards debunks the theory of evolution. In fact, warming theory suggests that you'd see trends toward heavier snows, because warmer air carries more moisture. This latest snowfall, though, is more likely the result of a strong El Niño cycle that has parked the jet stream right over the mid-Atlantic states.

Still, there's some rough justice in the conservatives' cheap shots. In Washington's blizzards, the greens were hoist by their own petard.

For years, climate-change activists have argued by anecdote to make their case. Gore, in his famous slide shows, ties human-caused global warming to increasing hurricanes, tornadoes, floods, drought and the spread of mosquitoes, pine beetles and disease. It's not that Gore is wrong about these things. The problem is that his storm stories have conditioned people to expect an endless worldwide heat wave, when in fact the changes so far are subtle.

Other environmentalists have undermined the cause with claims bordering on the outlandish; they've blamed global warming for shrinking sheep in Scotland, more shark and cougar attacks, genetic changes in squirrels, an increase in kidney stones and even the crash of Air France Flight 447. When climate activists make the dubious claim, as a Canadian environmental group did, that global warming is to blame for the lack of snow at the Winter Olympics in Vancouver, then they invite similarly specious conclusions about Washington's snow -- such as the Virginia GOP ad urging people to call two Democratic congressmen "and tell them how much global warming you get this weekend."

Argument-by-anecdote isn't working. Consider the words of Sen. Jeff Bingaman (D-N.M.), chairman of the energy committee, who told The Hill newspaper last week that the snow "makes it more challenging" to make the case about global warming's danger to people who aren't "taking time to review the scientific arguments."

Scientific arguments, too, are problematic. In a conference call arranged Thursday by the liberal Center for American Progress to refute the snow antics of Inhofe et al., the center's Joe Romm made the well-worn statements that "the overwhelming weight of the scientific literature" points to human-caused warming and that doubters "don't understand the science."

The science is overwhelming -- but not definitive. Romm's claim was inadvertently shot down by his partner on the call, the Weather Underground's Jeff Masters, who confessed that "there's a huge amount of natural variability in the climate system" and not enough years of measurements to know exactly what's going on. "Unfortunately we don't have that data so we are forced to make decisions based on inadequate data."

The scientific case has been further undermined by high-profile screw-ups. First there were the hacked e-mails of a British research center that suggested the scientists were stacking the deck to overstate the threat. Now comes word of numerous errors in a 2007 report by the U.N.'s Intergovernmental Panel on Climate Change, including the bogus claim that the Himalayan glaciers would disappear in 25 years.

For those concerned about warming, it's time for a shift in emphasis. Fortunately, one has already been provided to them by Sen. Lindsey Graham (R-S.C.), who has done more than any Democrat to keep climate legislation alive this year. His solution: skip the hurricanes and Himalayan glaciers and keep the argument on the hundreds of billions of dollars spent annually on foreign oil, some of that going to terrorists rather than to domestic job creation.

Al Gore, for one, seems to realize it's time for a new tactic. New TV ads released during last week's blizzards by Gore's climate advocacy group say nothing about climate science. They show workers asking their senators for more jobs from clean energy.

That's a good sign. If the Washington snows persuade the greens to put away the slides of polar bears and pine beetles and to keep the focus on national security and jobs, it will have been worth the shoveling.